Synthetic ATF. The capacity increase is not excessive. Other brands hold four or more extra quarts which is of limited benefit since the filter will be mounting in the same location. If the extra fluid depth is excessive, the filters suction opening will be a greater distance from the bottom of the pan so the cooled fluid may not always be pulled in. An exception is the Ford E4OD / 4R100 PML Trans. Pan which has a 3 quart to 3-1/2 quart volume increase. The added volume is because the pan has a large surface area and increasing the depth by the standard PML amount results in a larger volume. The gasket flange is thick and rigid. We have seen the inexpensive die cast pans leak because the flange is very thin and not very rigid. The PML flange is thick enough to resist losing clamping force between bolts due to the aluminum being subjected to alternating hot and then cold conditions. Check for Special Deals that include a greatly reduced price when a tapped temperature gauge is included.